In 1985, about 11 percent of the nine million adolescent girls in the United States became pregnant; almost half delivered babies. The adverse social, economic and medical sequelae of adolescent pregnancy, for both mothers and infants, are well-documented. Data from several clinical studies suggest that adequate nutrition and prenatal care can mitigate some of these problems, especially for high-risk groups such as adolescents. Improved nutrition and access to prenatal care are principal goals of the Special Supplemental Food Program for Women, Infants and Children (WIC), a federal program established in 1973 to meet the nutritional needs of high-risk pregnant woman, infants, and children. The purpose of this study is to assess the effects of the WIC program on outcomes of pregnancies to women under the age of 20, using an econometric model applied to a large national sample of countries over the period 1975-1984. Pregnancy outcomes will be assessed through four dependent variables: birth weight, gestational age, neonatal mortality, and postneonatal mortality. This study differs from prior attempts to evaluate the WIC program in that the "structural" model to be developed will permit elucidation of the mechanisms by which WIC exerts its effects. Specifically, unlike previous evaluations, the model will delineate the effects on pregnancy outcome on the principal intermediate goals of the WIC program (nutritional supplementation and improved access to prenatal care), and will differentiate these from other factors that also could have influenced outcome during the study period. The combined medical and economic training of the principal investigator should offer an opportunity to meld clinical knowledge and economic theory in an evaluation of an important national program.